ATLANTA--The first woman executed in Georgia in 70 years cried and sang "Amazing Grace" before she died early Wednesday, according to a witness, following pleas by the pope and her children for her life to be spared. Kelly Gissendaner, 47, died by injection at 12:21 a.m. EDT at Georgia Diagnostic and Classification Prison in Jackson, a prison spokeswoman said. Gissendaner had been the lone woman on Georgia's death row after being sentenced for plotting the killing of her husband, Douglas, in 1997. In the execution chamber, Gissendaner prayed and called her former husband an "amazing man who died because of me," according to television reporter Jeff Hullinger, who witnessed the injection. Gissendaner was the 16th woman executed in the United States since the Supreme Court reinstated the death penalty in 1976. Pope Francis, who concluded a six-day U.S. trip on Sunday and is an outspoken opponent of the death penalty, had urged officials to commute Gissendaner's death sentence. But members of Georgia's Board of Pardons and Paroles were not swayed by her latest appeal for clemency, which emphasized her remorse and model behaviour in prison. Gissendaner's lawyers also noted she was not present when the crime was committed. The man who carried out the kidnapping and murder, Gissendaner's then-boyfriend, Gregory Owen, received a life sentence. The board refused Gissendaner's request on Tuesday to commute her sentence to life in prison and the U.S. Supreme Court later denied last-minute requests for a stay of execution. Prison spokeswoman Lisa Rodriguez-Presley said Gissendaner, who completed a theology program in prison, requested a final prayer before she died. Gissendaner's supporters included her three adult children and a former Georgia Supreme Court justice who said he was wrong to deny one of Gissendaner's earlier appeals. But the family of Doug Gissendaner said she showed him no mercy. "As the murderer," the family said in a statement before the execution, "she's been given more rights and opportunity over the last 18 years than she ever afforded to Doug who, again, is the victim here."